From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The development of sleeve valves, exhaust rings, and high-octane aviation fuels in the late 1930s.
| Identifier | ExFiles\Box 27\3\ Scan223 | |
| Date | 15th May 1939 guessed | |
| 17. Sleeve Valves Although there was little outwardly expressed interest in sleeve valves, and although both Pratt & Whitney and Wrights said that they were not interested to the extend of doing any work, there can still be little doubt that there is great activity in this direction. From outside scources one learned that Wrights at least were certainly running Single Cylinder units and probably two or three main engines, while from questions asked by a considerable number of people employed by the two firms it was obvious that much work is being done and that the usual early troubles with piston rings and sleeves are being experienced. I would say that there is considerable interest and activity but that the firms do not want it tobbe known how little progress they have made. uestions about piston and ring experience, thickness of sleeves, size of ports, timing, strength of sleeve, s arting, cylinder temperatures, and port burning were asked by different people at different times. Exhaust Rings As no visits were paid to Aircraft firms it was not possible to get much information on exhaust rings, but apparently welding trouble has been experienced with Inconel and 18/8 is favoured. On the Cyclone Duplex engine, in order to overcome the difficulty of manifolding 18 cylinders, front and rear rings have been adopted. Everyone talked of the new 100 Octane Safety Fuel, which will be cheap, and will shortly be available in commercial quantities. It is made by a catalysis process. With it, however, direct injection will have to be employed. 95 Octane fuel is specified for current use as this has the minimum Octane number which can be obtained under the present 100 Octane Army specifications. In the last six months of 1938, the U.S. Army used the following fuel:- | ||